CAJ | 학술논문

悬臂梁结构是小阻尼系统，模态阻尼对裂纹故障敏感，为了解决传统阻尼识别方法识别误差大的问题，创新性的提出利用内积模极值法和循环相减相结合进行阻尼诊断的方法。首先，应用内积模极值法识别出信号的某一阶模态参数，从原信号中除去该阶估计信号。然后，重复这种内积运算和相减步骤，形成迭代，模态之间的相互干扰在迭代计算过程中得到消减，提高各阶阻尼的识别精度。实验采用该方法进行悬臂梁阻尼识别，并改变悬臂梁阻尼模拟裂纹出现，当粘贴一片阻尼片时，在60 Hz和200 Hz附近模态的阻尼分别产生了0.000019和0.000112的变化。结果表明，内积模极值法和循环相减相结合可以准确识别出阻尼的微小变化，在工程上可以让阻尼成为一个重要的参数参与悬臂梁的故障诊断。
현비량결구시소조니계통，모태조니대렬문고장민감，위료해결전통조니식별방법식별오차대적문제，창신성적제출이용내적모겁치법화순배상감상결합진행조니진단적방법。수선，응용내적모겁치법식별출신호적모일계모태삼수，종원신호중제거해계고계신호。연후，중복저충내적운산화상감보취，형성질대，모태지간적상호간우재질대계산과정중득도소감，제고각계조니적식별정도。실험채용해방법진행현비량조니식별，병개변현비량조니모의렬문출현，당점첩일편조니편시，재60 Hz화200 Hz부근모태적조니분별산생료0.000019화0.000112적변화。결과표명，내적모겁치법화순배상감상결합가이준학식별출조니적미소변화，재공정상가이양조니성위일개중요적삼수삼여현비량적고장진단。
The cantilever beam structure is small damping system, modal damping is sensitive to crack fault. In order to solve the problem that traditional damping identification method has big er-ror, the inner product modulus maximum method combined with circular subtraction is proposed to do damping identification. Firstly, the inner product modulus maximum method is applied to iden-tify a modal parameter of signals for subtracting the estimated signal from original signals. Then, repeat these steps of this inner product operation and subtraction to become the iteration. The mo-dal interference is decreased in the process of iteration, and the identification of each modal is more accurate. This method is applied to diagnose cantilever beam damping in the experience, and change the cantilever beam damping to simulate the crack. When one damping slice pasted on the beam, the damping produced the change of 0. 000 019 and 0. 000 112 in the vicinity of 60 Hz and 200 Hz, respectively. Results show that the inner product modulus maximum method combined with circular subtraction can accurately identify the damping small change. The damping will be recognized as an important parameter in the fault diagnosis of beam.